Local government spokesman Edward Davey estimated the average rate to bring in the same revenue would be about 3p and 3.5p in the pound.

It would mean that with a new ‘supertax’ rate of an additional 20p on incomes over £100,000, the highest rate of income tax under a Liberal Democrat Government could top 53%.

Davey told conference delegates that this year’s council tax rises had taken the tax passed the limit of acceptability and had resulted in ‘murmurings of civil disobedience among grass roots campaigning groups’.

He said: ‘How can it be right that the poorest pensioners pay six times more of their income in council tax than the richest non-pensioners?’

A motion passed by delegates also called for a fairer system of central government grants and the restoration to individual local authorities of control over business rates which they would then be allowed to switch to a site-value basis.